shikyakumon 四脚門

Also an old name read yotsuashimon and sometimes written 四足門; also called ikken-ikkomon 一間一戸門. A four-legged gate. A single-storied structure composed of two large main pillars, centered and in line with the ridge. Usually, there are two square posts, sodebashira 袖柱, in front and behind of the main pillars. The latter are considered secondary legs, hence a 4-legged gate. These support the wall purlins *gawageta 側桁. Generally, the roof is gabled *kirizuma yane 切妻屋根, and has frog-leg struts *kaerumata 蟇股, in the gable ends. Penetrating tie beams *nuki 貫, connect the secondary and main pillars. Rainbow beams *kōryō 虹梁 run transversely. Bracket complexes *tokyō 斗きょう are positioned on the tie beams to carry the roof structure. Roofs are covered with tile or cypress bark. 

The shikyakumon is used only for high-ranking temples, or Imperial Palace gates. The oldest extant 4-legged gate is at Shin'yakushiji 新薬師寺 (late 12th-early 13th century) in Nara. It has braces *udegi 腕木 instead of bracket complexes, and the frog-leg struts are placed directly on these braces. Other examples include: Nishina Shinmeigū Chūmon 仁科神明宮中門 (1636) in Nagano Prefecture, which is a 4-legged gate with round secondary posts; Jūrin-in Minamimon 十輪院南門 (late 12th-early 13th century) in Nara, which is a small 4-legged gate with gabled roof and plank eaves and was used as an aristocratic residence; Sōgenji 宗源寺, 4-legged gate at Hōryūji 法隆寺 (1237) in Nara. There are also 4-legged gates made with undulating bargeboards *karahafu 唐破風. Undulating bargeboards on the front and back of a gate are found at Kitano Tenmangū Chūmon 北野天満宮中門 (1607) in Kyoto.